1. Technical Field
Example embodiments relate to an image sensor, and more particularly, to a back-illuminated image sensor.
2. Description of the Related Art
An image sensor is a device that transforms incident light to an electric signal. A charge coupled device (CCD) image sensor and a complementary metal oxide semiconductor (CMOS) image sensor may be used. To improve sensing performance, a backside illuminated image sensor (BIS) that performs photoelectric transformation in response to an incident light passing through a back surface of a semiconductor substrate has been used.